Devices of a client network are connected to one another through a physical channel provided by a service network, and specifically, service network devices of two ends (that is, a source end and a destination end) are connected to two client network devices respectively. When a signal is transmitted, a source end device of the service network encapsulates and adapts a client network signal into a carrier signal that can be transmitted in the service network, and transmits the carrier signal to the destination end of the service network, and the destination end of the service network restores the client signal and sends the restored client signal to the client network device. When a rate of the client network signal is higher than that of the carrier signal in the service network, it is necessary to combine a plurality of carrier signals in the service network to transmit the client signal. Therefore, it is a problem to compute a path that satisfies client-side network signal transmission in a service-side network.
One solution of computing a path in the prior art is that: A node receiving a client-side service request serves as a head node of a path, and the head node is responsible for computing the path of the client-side service request.
When the service-side network is of a very large scale, the network is divided into a plurality of smaller network domains so that topology information about each network domain may not be flooded to other network domains, thus preventing network congestion caused by excessive flooded topology information in the network. Another solution of computing a path in the prior art is that: A node receiving a client-side service request serves as a head node of a domain where the node is located, so as to compute a path in the domain, a node in the domain where the head node is located and which is connected to other domains selects a next-domain node on a path that satisfies the client-side service demands, the next-domain node is responsible for computing the path in the domain in which the next-domain node is located, and a node in a domain where the next-domain node is located and which is connected to other domains selects a next-domain node on a path that satisfies the client-side service demands, so as to compute and obtain a cross-domain path finally.
However, for the aforementioned one solution of computing a path in the prior art, each node may serve as a head node to be responsible for computing a path, and when the network is of a very large scale, path computation may increase the burden of the node due to limited processing capability of the node. As for the aforementioned another solution of computing a path in the prior art, cross-domain computation can be accomplished only when a plurality of nodes in the network participates in the computation, and the solution is rather complex.